Supercron produces countless syslog entries when using syslog instead of drupal logging. Below is a message that constantly appears in logs:
/admin/settings/supercron|1||Table 'db_drupal.watchdog' doesn't exist query: SELECT * FROM watchdog WHERE type='cron exception' ORDER BY wid DESC in /public_html/sites/all/modules/supercron/supercron.module on line 292.

Since I'm using syslog, watchdog table simply doesn't exist.